Judy Ventura/Sandbox1

A CBI Molecule being studied in the University of Massachusetts Amherst Chemistry-Biology Interface Program at UMass Amherst and on display at the Molecular Playground.

β-Galactosidase is a hydrolase enzyme that catalyzes the hydrolysis of beta- galactosidase into monosaccharides (carbon/energy source). Is encoded by the lacZ gene of the lac operon in E.coli. It is a large 120 kDa, >1000 amino acids) protein that forms a tetramer.

It is commonly used as a reporter molecule in genetics and molecular biology. Usually, experiments are designed so that the β-Galactosidase concentration in the cell is a readout for some aspect of a system being studied. When the β-Galactosidase cleaves the substrate o-nitrophenyl-b-D-galactopyraniside (ONPG), o-nitrophenol is released. This compound has a yellow color, and absorbs 420 nm light. To measure β-Galactosidase activity the accumulation of yellow color (increase 420 nm absorbance)/minute is monitored.

All Molecule

Subunits